A team of Japanese scientists from the University of Tsukuba and the University of Tokyo has discovered a neural center responsible for the REM sleep phase. The study was published in the scientific journal Cell. REM sleep phase usually occurs after 60-80 minutes after falling asleep. During this time, a person dreams and key cognitive skills, including learning and creativity abilities, are developed. Neuroscientists in laboratory mice have studied a cluster of neurons in the upper part of the brainstem called the pontine. In rodents, these neurons are connected to neurons in the medulla oblongata. According to the scientists, the neuronal loop discovered may function as the main circuit of REM sleep. When the team removed the bridge neurons from the loop, the animals showed reduced sleep and impaired muscle relaxation during REM sleep. However, when the bridge neurons extending to the medulla oblongata were activated, the mice entered the REM phase of REM sleep more quickly, and the number and duration of REM episodes during sleep increased. It appeared that neurons in the medulla oblongata actively stimulate the REM phase of REM sleep by projecting to multiple regions involved in the activity of this phase. Activation of these neurons in mice caused direct transitions from wakefulness to REM sleep. According to the researchers, the discovery may contribute to the treatment of various sleep disorders, including narcolepsy.